Grain bins are large, generally cylindrical sheds for storing grain. An exemplary grain bin 10 is shown in FIG. 1. An auger (not shown) is disposed within the bin 10 adjacent the bottom of the bin 10. The auger is electrically powered and is run to remove grain from the bin 10 via a discharge opening 12. When the auger is actuated, the grain inside the bin 10 drains downward in a funnel-like fashion.
As illustrated in FIG. 1, grain bins are provided with an access opening 14 in their roofs through which a person may enter the bin 10. The access opening 14 is usually provided with a hinged door or manhole cover 16 (see FIG. 1) to protect the grain stored in the bin 10 from weather elements such as rain. From time to time, grain can become jammed in the bin 10 such that the auger does not move or, if it moves, little or no grain is discharged. Although it is quite dangerous to do so, individuals sometimes respond to such jamming by entering the grain bin 10 and jumping in the grain to release the jam. Sometimes this process is performed while the auger is supplied with power (i.e., with the auger in the "on" or "run" condition). If a person jumping in the grain releases the jam with the auger in the run state, the auger can start to pull the grain downward in a funnel like manner. If a person is in the grain bin 10 when the grain starts to flow in this manner, they will quickly be pulled under the grain and may subsequently be suffocated.